<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</meta>
<title>F().opacity演示</title>
<style type="text/css">
.box{width:100px; height:100px; background-color:#ff0000;}
</style>
<script type="text/javascript" src="../../1st.js"></script>
</head>
<body>
<div id="mask" class="box">5555555</div>

<script type="text/javascript">
F("mask").opacity(0.5);
alert(F("mask").opacity());
</script>
</body>
</html>